Small, low-grade ampullary neuroendocrine tumor presenting with metastasis and multiple synchronous tumors in a patient with neurofibromatosis type 1: a case report with literature review.

Neurofibromatosis type 1 (NF1) is a tumor syndrome and one of the most common genetic disorders. Patients have an increased risk of developing neurologic and gastrointestinal (GI) neoplasms, but GI lesions are often underrecognized since most cases are asymptomatic. It is extremely rare to see multiple types of abdominal tumors synchronously in NF1. In this case, we describe a patient presenting with a small, low-grade periampullary neuroendocrine tumor (NET) that underwent endoscopic submucosal dissection and later pancreaticoduodenectomy (Whipple procedure). This led to findings of lymph node and distant metastasis of her NET, and the incidental discovery of gastrointestinal stromal tumors, extensive pancreatic intraepithelial neoplasia, and main duct and side branch intraductal pancreatic mucinous neoplasm. The synchronous presence of these lesions has not been reported in the literature.